Method and apparatus to read different types of data carriers, such as RFID tags and machine-readable symbols, and a user interface for the same

ABSTRACT

A data carrier reader includes an RFID tag reading section and a machine-readable symbol reading section, which can contain some common components. The reader is operable in an RFID tag reading mode and/or a symbol reading mode. The reader provides a consistent and intuitive user interface within, and between, the operating modes. The user interface can include visual, aural and tactile indicators. The visual indicators can include a pattern displayed by indicators on the reader, or projected onto or near the data carrier.

TECHNICAL FIELD

[0001] This application relates to methods and apparatus for readingdata carriers such as machine-readable symbols (e.g., barcode symbols,area and/or matrix code symbols) and wireless memory devices (e.g., RFIDtags).

BACKGROUND OF THE INVENTION

[0002] A variety of methods exist for tracking and providing informationabout items. For example, inventory items typically carry printed labelsproviding information such as serial numbers, price, weight, and size.Some labels include data carriers in the form of machine-readablesymbols that can be selected from a variety of machine-readablesymbologies, such as bar code, and/or area or matrix code symbologies.The amount of information that the symbols can contain is limited by thespace constraints of the label. Updating the information in thesemachine-readable symbols typically requires the printing of a new labelto replace the old label.

[0003] Data carriers such as memory devices provide an alternativemethod for tracking and providing information about items. Memorydevices permit the linking of large amounts of data with an object oritem. Memory devices typically include a memory and logic in the form ofan integrated circuit (“IC”) and means for transmitting data to and/orfrom the device. For example, a radio frequency identification (“RFID”)tag typically includes a memory for storing data, an antenna, an RFtransmitter, and/or an RF receiver to transmit data, and logic forcontrolling the various components of the memory device. RFID tags aregenerally formed on a substrate and can include, for example, analog RFcircuits and digital logic and memory circuits. The RFID tags can alsoinclude a number of discrete components, such as capacitors,transistors, and diodes.

[0004] RFID tags can be passive, active or hybrid devices. Activedevices are self-powered, by a battery for example. Passive devices donot contain a discrete power source, but derive their energy from an RFsignal used to interrogate the RFID tag. Passive RFID tags usuallyinclude an analog circuit that detects and decodes the interrogating RFsignal and that provides power from the RF field to a digital circuit inthe tag. The digital circuit generally executes all of the datafunctions of the RFID tag, such as retrieving stored data from memoryand causing the analog circuit to modulate the RF signal to transmit theretrieved data. In addition to retrieving and transmitting datapreviously stored in the memory, the RFID tag can permit new oradditional information to be stored in the RFID tag's memory, or canpermit the RFID tag to manipulate data or perform some additionalfunctions. RFID tags are available from a number of manufacturers,including Texas Instruments, Dallas, Tex., and Omron of Japan.

[0005] Another form of memory device is an optical tag. Optical tags aresimilar in many respects to RFID tags, but rely on an optical signal totransmit data to and/or from the tag.

[0006] Additionally, touch memory data carriers are available, forexample touch memory devices from Dallas Semiconductor of Dallas, Tex.Touch memory devices are similar to RFID tags but require physicalcontact with to store and retrieve data.

[0007] A user typically secures a data carrier to an item, such as agood, product, or container by way of a pressure sensitive adhesive. Thedata carrier often encodes information specifically relating to the itemsuch as identifying or destination information. An individual, such as acheckout or inventory clerk, can retrieve data about any given item, forexample, by scanning the machine-readable symbol or interrogating the RFtag, optical tag, or touch memory device. Access to the data can beuseful at the point of sale, during inventory, during transportation, orat other points in the manufacture, distribution, sale, or use of thetagged item.

[0008] Relatively high cost is one of the drawbacks of memory devices,thus, many applications rely on the less expensive printedmachine-readable symbols. Another significant drawback is the difficultyof identifying a particular memory device from a group of memorydevices. It is particularly difficult to associate the information readfrom the RFID tag with a physical item or container. The ability to readdata from different types of data carriers, for example machine-readablesymbols and RFID tags, and/or to associate and manipulate such data canprovide numerous benefits in the automatic data collection (“ADC”)industry.

SUMMARY OF THE INVENTION

[0009] In one aspect a data carrier reader includes an RFID tag readingsection and a machine-readable symbol reading section, which can containsome common components. The reader is operable in an RFID tag readingmode and/or a symbol reading mode. The reader provides a consistent andintuitive user interface within, and between, the operating modes. Theuser interface can include visual, aural and tactile indicators. Thevisual indicators can include a pattern displayed by indicators on thereader, or projected onto or near the data carrier.

[0010] In another aspect, a data carrier reader is capable of executinga number of different reading methods. A method for reading single RFIDtags can store read data to a buffer for eventual transmission to ahost, and can suppress redundant data. Another method identifies allRFID tags having a characteristic data string that appears on a list. Incontrast, another method identifies any RFID tags having acharacteristic data string that does not appear on the list. Stillanother method associates data read from an RFID tag with a particularobject or item using a data coded in a machine-readable symbol. In afurther method, the machine-readable symbol is automatically read whenthe RFID tag is within a predetermined proximity of the reader. In eachmethod, a consistent and intuitive output can be provided to the user toidentify the successful and unsuccessful operations such as reading anRFID tag or machine-readable symbol.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the drawings, identical reference numbers identify similarelements or acts. The sizes and relative positions of elements in thedrawings are not necessarily drawn to scale. For example, variouselements may be arbitrarily enlarged and positioned to improve drawinglegibility.

[0012]FIG. 1 is a partial block diagram, partial front elevational viewof a facility including a data carrier reader reading data carrierscarried by a number of items, the reader communicate with a host throughan interface.

[0013]FIG. 2 is a functional block diagram of the reader according toone embodiment of the invention.

[0014]FIG. 3 is a top plan view of the reader of FIG. 2.

[0015]FIG. 4 is a partial top plan view of an alternative set of visualindicators for the reader of FIG. 2.

[0016] FIGS. 5A-5C together form a chart of selected input and outputsignals for operating the reader of FIG. 2 and the visual indicators ofFIG. 4.

[0017]FIG. 6 is a top plan view of a graphic display of the reader ofFIG. 3.

[0018]FIG. 7 is a top plan view of an alpha-numeric display of thereader of FIG. 3.

[0019]FIG. 8 is a flowchart showing a method of reading single RFIDtags.

[0020]FIG. 9 is a flowchart showing a method of determining when areader is finished reading RFID tags.

[0021]FIG. 10 is a flowchart showing a method of reading multiple RFIDtags.

[0022]FIG. 11 is a flowchart showing a method of performing an inclusivesearch of RFID tags.

[0023]FIG. 12 is a flowchart showing a method of performing an exclusivesearch of RFID tags.

[0024]FIG. 13 is a flowchart showing a method of associating data froman RFID tag with an item using a machine-readable symbol.

[0025]FIG. 14 is a flowchart showing a method of automatically imaging amachine-readable symbol based on proximity to an RFID tag to associatedata from an RFID tag with an item using the machine-readable symbol.

DETAILED DESCRIPTION OF THE INVENTION

[0026] In the following description, certain specific details are setforth in order to provide a thorough understanding of variousembodiments of the invention. However, one skilled in the art willunderstand that the invention may be practiced without these details. Inother instances, well-known structures associated with RFID tags, RFIDtag readers, one- and two-dimensional symbologies, symbol readers,microprocessors and communication networks have not been shown ordescribed in detail to avoid unnecessarily obscuring descriptions of theembodiments of the invention.

[0027] The headings provided herein are for convenience only and do notinterpret the scope or meaning of the claimed invention.

[0028] Data Carrier Reader

[0029]FIG. 1 shows a data carrier reader 10 reading one or more of anumber of data carriers, such as the RFID tags 12 on the containers oritems 14. The reader 10 includes a head 16, a handle 18 and a trigger20. An interface 22 can couple the reader 10 to a host 23, such as acentralized computer, as described in detail below.

[0030] The tags 12 can take the form of an RFID tag 12A that carries amachine-readable symbol 24A on a visible surface of the tag.Alternatively, the tags 12 can take the form of a separate RFID tag 12Band machine-readable symbol 24B. The separate RFID tag 12B andmachine-readable symbol 24B can be physically associated, for example,securing each to the same physical object, such as the item 14. The RFIDtag 12A, 12B and machine-readable symbol 24A, 24B can contain logicallyassociated information, for example information related to the item 14to which the tags 12 are secured, such as identifying and/or shippinginformation.

[0031] As shown in FIG. 2, the reader 10 contains an RFID tag readingsection 30, a symbol reading section 32, a user input section 34, a useroutput section 36, and a communications section 38 all coupled by a bus40. The bus 40 provides data, commands and/or power to the varioussections 30-38. The reader 10 can include an internal power source suchas a rechargeable battery (not shown) or can receive power from anexternal power source such as a wall outlet by way of an electrical cord(not shown). Each of these sections 30-38 will be described individuallybelow, although in the illustrated embodiment some of these sectionsshare common components.

[0032] RFID Tag Reading Section

[0033]FIG. 2 shows the RFID tag reading section 30 of the data carrierreader 10 including an antenna 42 coupled to a radio 44. The radio 44 iscoupled via the bus 40 to a microprocessor 46 and a random access memory(“RAM”) 48. The RAM 48 can include a characteristic data string buffer49 to temporarily store characteristic data strings, as will beexplained in detail below. Alternatively, the reader 10 can include adiscrete characteristic data string buffer (not shown). While FIG. 2shows a single microprocessor 46, the data carrier reader 10 may includeseparate dedicated processors for each of the RFID tag and symbolreading sections 30, 32.

[0034] While a dipole antenna 42 is shown, the data carrier reader 10can employ other antenna designs. Of course, the antenna can be selectedto achieve a particular focus, for example, a highly directional antennacan enhance the ability of the reader 10 to select a single RFID tag 12out of a group of RFID tags. The radio 44 can take the form of atransceiver capable of transmitting and receiving at one or more of thefrequencies commonly associated with RFID tags 12 (e.g., 350 kilohertz,400 kilohertz, 900 kilohertz). While these frequencies typically fallwithin the radio frequency range of the electromagnetic spectrum, theradio 44 can successfully employ frequencies in other portions of thespectrum. Antenna design and radios are generally discussed in The ARRLHandbook for Radio Amateurs, 76^(th) Ed., American Radio Relay League,Newington, Conn., U.S.A. (1999) (ISBN: 0-87259-181-6), and commonlyassigned patent application U.S. Ser. No. 09/280,287, filed Mar. 29,1999, entitled ANTENNA STRUCTURES FOR WIRELESS COMMUNICATIONS DEVICE,SUCH AS RFID TAG (Atty. Docket No. 480062.648).

[0035] A read only memory (“ROM”) 50 stores instructions for executionby the microprocessor 46 to operate the radio 44. As used in thisherein, ROM includes any non-volatile memory, including erasablememories such as EEPROMs. The programmed microprocessor 46 can controlthe radio 44 to emit an interrogation signal, including any requiredpolling codes or encryption, and to receive a return signal from an RFIDtag 12A, 12B. The programmed microprocessor 46, RAM 48, radio 44 andantenna 42 thus form the RFID reading section 30.

[0036] Symbol Reading Section

[0037]FIG. 2 also shows the symbol reading section 32 of the datacarrier reader 10 including an image sensor 52 and an illuminationsource, such as the laser 53. The image sensor 52 can take the form of aone- or two-dimensional charge coupled device (“CCD”) array.Alternatively, the reader 10 can employ other known imaging devices, forexample laser scanners or Vidicons. In certain embodiments, the datacarrier reader 10 can omit the illumination source, for example wherethe image sensor 52 is a two-dimensional CCD array operable with ambientlight. Alternatively, the data carrier reader 10 can rely on otherillumination sources, such as light emitting diodes (“LEDs”) or a strobelight, that can be positioned to illuminate a desired one of themachine-readable symbols 24A, 24B. The reader 10 can employ suitableoptics such as lens and mirrors (not shown) for directing lightreflected from the machine-readable symbol 24A, 24B to the image sensor52.

[0038] The reader 10 includes an analog-to-digital (“A/D”) converter 54,to transform the analog electrical signals from the image sensor 52 intodigital signals for use by the microprocessor 46. The bus 40 couples theimage data from the A/D converter 54 to the microprocessor 46 and theRAM 48. A portion of the RAM 48 can form an image buffer 56 fortemporarily storing data, such as a captured image data from the imagesensor 52. The ROM 50 contains instructions for the microprocessor 46,that permit the microprocessor 46 to control the image sensor 52 tocapture image data and to decode and/or manipulate the captured imagedata. The programmed microprocessor 46, RAM 48, image sensor 52, and A/Dconverter 54, thus form the symbol reading section 32.

[0039] Symbol reading and decoding technology is well-known in the artand will not be discussed in further detail. Many alternatives for imagesensors, symbol decoders, and optical elements that can be used in thereader 10 are taught in the book, The Bar Code Book, Third Edition, byRoger C. Palmer, Helmers Publishing, Inc., Peterborough, N.H., U.S.A.(1995) (ISBN 0-911261-09-5).

[0040] Communications Section

[0041] The communications section 38 includes a communications buffer 47and a communications port 49. The communications buffer 47 cantemporarily store incoming and outgoing data and/or commands where thecommunications speed of the reader 10 does not match the communicationsspeed of some external device, such as the interface 22 (FIG. 1). Thecommunications port 49 provides communications between the reader andexternal devices. While shown as a hardwire connection to the interface22 (FIG. 1), the communications port can be a wireless interface, andcan even employ the antenna 42 and radio 44 of the RFID tag readingsection 30. Additionally, the reader 10 can include the interface 22 asan integral part of the reader 10.

[0042] The interface 22 (FIG. 1) can provide communications over acommunications network 68 to the host 23, allowing transmissions of dataand/or commands between the reader 10 and the host 23. Thecommunications network 68 can take the form of a wired network, forexample a local area network (“LAN”) (e.g., Ethernet, Token Ring), awide area network (“WAN”), the Internet, or the World Wide Web (“WWW”).Alternatively or additionally, the communications network 68 can be awireless network, for example, employing infrared (“IR”), satellite,and/or radio frequency (“RF”) communications.

[0043] The host 23 can receive from each of a number of the readers 10,data collected from the RFID tags 12 and machine-readable symbols 24.The host 23 can use the data with a database, and can automaticallymanipulate the data, for example to automatically performing inventoryor to track shipments.

[0044] The host 23 can provide data and commands to each of a number ofthe readers 10. For example, the host can share data between the readers10, such as providing a list of either located or missing identifiers,as will be discussed in more detail below in reference to inclusive andexclusive searches. The host 23 can provide a command to toggle thereader 10 between an RFID tag reading mode and a symbol reading mode,which is described below in further detail. Thus, the host 23 cancommand, coordinate and share data between a number of readers 10.Commonly assigned patent application U.S. Ser. No. 09/______, filed,1999, entitled, “SYSTEM AND METHOD FOR AUTOMATICALLY CONTROLLING ORCONFIGURING A DEVICE, SUCH AS AN RFID READER” (Atty. Docket No.480062.672) contains teachings that can be used to automatically controlor configure the reader 10.

[0045] User Input Section

[0046] The user input section 34 includes the trigger 20, the modeswitch 34, and can include a user input device 58. The bus 40 couplesthe mode switch 34 to the microprocessor 46. In response to selection ofthe mode switch 34, the microprocessor 46 switches between the symbolreading mode and the RFID tag reading mode, for example by togglingbetween the two operating modes. The reader 10 can employ additionaloperating modes, or switching positions as desired, for example a switchposition that places the reader 10 in an OFF state or a WAIT state toconserve energy.

[0047] In the symbol reading mode, the microprocessor 46 operates theimage sensor 52 to image one of the machine-readable symbols 24A, 24B.The microprocessor 46 decodes the imaged symbol to retrieve the dataencoded in the machine-readable symbol 24A, 24B, such as a respectiveidentifier. In the RFID tag reading mode, the microprocessor 46 operatesthe radio 44 to emit an interrogation signal and to receive a responsefrom one or more of the RFID tags 12A, 12B to the interrogation signal.The microprocessor 46 decodes the response signal to retrieve the dataencoded in the RFID tag 12A, 12B, such as a respective identifier.

[0048] The mode switch 34 can be a membrane switch, mounted to theexterior of the reader 10 for easy selection by the user. The modeswitch 34 can additionally, or alternatively, be implemented in thesoftware to supplement or replace the user selectable mode switch on theexterior of the reader 10. The software implemented switch isparticularly useful where the host 23 (FIG. 1) controls the operatingmode of the reader 10. Alternatively, the mode switch 34 can beimplemented as an icon on a touch sensitive display 74. In furtheralternatives, the trigger 20 can function as the mode switch 37. In oneinstance, the number of successive trigger pulls or activations candetermine the operating mode. For example, two successive trigger pullscan select the symbol mode, while three successive trigger pulls selectsthe RFID mode; or a single trigger pull can cause the reader 10 to reada symbol while a double trigger pull toggles between the symbol and RFIDmodes. Alternatively, the duration of trigger activation can determinethe operating mode. For example, a trigger pull of under 0.5 seconds canselect the symbol mode, while a trigger pull of longer than 0.5 secondscan select the RFID mode; or a trigger pull of under 0.5 seconds cancause the reader 10 to read a symbol while a trigger pull of over 0.5seconds toggles the reader between the symbol and RFID modes.Additionally, or alternatively, the mode switch can be contextsensitive, switching modes based on data read from a previously readdata carrier 12A, 12B, 24A, 24B. For example, a previously read RFID tag12A can indicate the existence of a symbol 24A. In response, the datacarrier reader 10 can automatically switch into symbol mode and read thesymbol 24A associated with the RFID tag 12A.

[0049] The bus 40 also couples the trigger 20 to the microprocessor 46.In response to activation of the trigger 20, the microprocessor 46 cancause the image sensor 52 to image one of the machine-readable symbols24A, 24B when the reader 10 is operating in the symbol reading mode. Inat least one embodiment, the microprocessor 46 can also cause the radio44 and antenna 42 to emit an interrogation signal in response to theactivation of the trigger 20 while in the reader 10 is operating in theRFID tag reading mode.

[0050] The user input device 58 can take the form of a keypad 60 (FIG.3), mouse, touch screen and/or other user operable device to inputinformation and/or commands to the reader 10. The bus 40 couples theuser input device 58 to the microprocessor 46, to allow the user toenter data and commands.

[0051] User Output Section

[0052] The user output section 36 includes human-perceptible visual andaudio indicators 62, 64 respectively. The bus 40 couples the visual andaudio indicators 62, 64 to the microprocessor 46 for control thereby.The visual indicators 62 can take a variety of forms, for example: lightemitting diodes (“LEDs”); a graphic display such as a liquid crystaldisplay (“LCD”), and/or an alpha-numeric display such as a 7-segmentdisplay. The audio indicator 64 can take the form of one or moredynamic, electrostatic or piezo-electric speakers 66. The speaker 66 isoperable to produce a variety of sounds (e.g., Clicks and Beeps), and/orfrequencies (e.g., tones), and to operate at different volumes. Thereader 10 can also include tactile indicators such as a vibratingmember. The specific operation of the user output section 36 isdiscussed in more detail below.

[0053]FIG. 3 shows a portion of the user interface located on the head16 of the reader 10. The user interface includes the elements of theuser input section 34, such as the trigger 20, the mode switch 34 andthe keypad 60. The user interface also includes the elements of the useroutput section 36 including the visual indicators 63 and the speaker 66.In particular, the visual indicators 62 in the illustrated embodimentinclude a set of RFID related LEDs 70, a set of machine-readable symbolrelated LEDs 72, and a display 74.

[0054] The data carrier reader 10 can additionally, or alternatively,employ the laser 53 as the visual indicator. The laser can besuccessively pulsed or flashed according to a set of predefinedhuman-recognizable temporal patterns to provide information to the user,such as user indications corresponding to the various reader operationsand/or the responses from the date carriers 12A, 12B, 24A, 24B.Employing the laser 53 as a portion of the user interface provides anumber of distinct benefits. For example, operating the laser 53 toprovide human-recognizable patterns can eliminate the need for othervisual indicators 62. The data carrier reader 10 can employ multipleillumination sources such as lasers 53 or LEDs of different colors, oran illumination source capable of producing a number of different colorsto provide the appropriate user indications, as set out in FIGS. 5A-5C.As discussed in detail below, the human-recognizable patterns can Sakethe form of a predefined sequence of laser flashes of one or morecolors, separated by time (i.e., temporal pattern).

[0055] The visual and audio indicators 62, 64 are configured to providean intuitive user interface consistent across the RFID tag and symbolreading modes. For example, the RFID tag related and symbol related LEDsets 70, 72 each contain green 76, 78, yellow 80, 82 and red 84, 86LEDs, in an order or pattern that is consistent between the sets. Theparticular LED 76-86, as well as the number and/or pattern of flashes,is set such that the same color LEDs flash the same pattern foranalogous RF tag reading and symbol reading activities. For example, theyellow LED 80 in the RFID tag related set 70 flashes during the readingof one of the RFID tags 12A, 12B (FIG. 1), while the yellow LED 82 inthe machine-readable symbol related set 72 flashes during the reading ofone of the machine-readable symbols 24A, 24B (FIG. 1). The reader 10responds to a successful read of the RFID tag 12A, 12B ormachine-readable symbol 24A, 24B by illuminating the corresponding greenLED 76, 78, respectively, for a set period of time such as 5 seconds.The red LEDs 84, 86 can indicate unsuccessful or incomplete operations.The user receives visual feedback, where the color, position andsequence of the visual indicators 62 is consistent within, and acrossthe RFID tag and symbol operating modes. Consistent feedback can reducetraining time and costs, and can lead to more efficient operation of thereader 10.

[0056] Similar to the visual indicators 62, the speaker 66 providesconsistent feedback within and across the operating modes. In theillustrated embodiment, the speaker 66 emits a “beep” or a “click”sound, although the speaker 66 can emit different and/or additionalsounds. The speaker 66 can emit, for example, a single beep each timeeither an RFID tag 12A, 12B or a machine-readable symbol 24A, 24B issuccessfully read. When searching a field of RFID tags 12A, 12B for oneor more particular tags, the speaker 66 can emit a click for eachnon-match and a beep for each match.

[0057] The user interface can also include an ON/OFF indicator 97,and/or a Low Power indicator 99 to identify the operating condition ofthe reader 10.

[0058]FIG. 4 shows an alternative set of visual indicators for thereader 10. This alternative embodiment, and those alternativeembodiments and other alternatives described herein, are substantiallysimilar to previously described embodiments, and common acts andstructures are identified by the same reference numbers. Onlysignificant differences in operation and structure are described indetail below.

[0059] The reader 10 of FIG. 4 employs only three LEDs to simplifyswitching while providing the human-perceptible visual indications. Atwo state LED serves as the machine-readable symbol related indicator87. The machine-readable symbol indicator 87 produces no light in an OFFstate and a Green light in an ON state. A three state LED serves as theRFID related indicator 89. The RFID related indicator 89 produces aGreen light in first ON state, a Yellow light in second ON state, and NOlight in an OFF state. A two state LED serves as the ON/OFF indicator97. The ON/OFF indicator produces a Yellow light, or No light. TheON/OFF indicator is proximate the machine-readable symbol related andRFID related indicators 87, 89. In FIG. 4, the mode switch 34 takes theform of a toggle or slider switch, having a neutral position (center), asymbol mode position (left of center) and an RFID mode position (rightof center). The positions are consistent with the corresponding visualindicators 87, 89, respectively.

[0060] FIGS. 5A-C describe a variety of input and outputs signals forthe reader 10, and particularly for the audio indicator 64 and laser 53of FIG. 2, and for the visual indicators 87, 89, 97 of FIG. 4. While thetable is self-explanatory, a brief description of the columns follows.Column 31 defines a reader status or error conditions corresponding toreader activities. Column 33 describes the operation of the visualindicators 87, 89, 97 of FIG. 4, in response to the various readerstatus or errors conditions. Similarly, column 35 describes theoperation of the audio indicator 64 in response to the various readerstatus or error conditions 33. Column 37 describes the operation of thelaser to produce the desired human-recognizable patterns correspondingto the various reader status or errors conditions 31. Column 39describes messages for display on the display 74 corresponding to thevarious reader status or errors conditions 31. Column 41 describesPDT/Host messages corresponding to the various reader status or errorsconditions 31. Column 43 describes data and/or error codes sent to thehost 33, corresponding the various reader status or errors conditions31. As discussed above, these user indications provide a consistentinterface for the user within and across the operating modes, permittingthe user to efficiently operate the reader 10.

[0061] The display 74 can additionally, or alternatively, provide theuser other visual indications. For example, a graphical display 88 (FIG.6), can employ a first set of icons 90 to indicate RFID tag activitiesand a second set of icons 92 to indicate symbol reading activities.(Note, typically only a single icon will be displayed at a time,although multiple icons are shown in FIG. 6 for the convenience of thisdescription.) For example, screen icons 81, 83 and 85 can represent RFIDreading, successful reading of the RFID tag 12A, 12B, and unsuccessfulreading of RFID tag 12A, 12B, respectively. Similarly, screen icons 91,93 and 95 can represent machine-readable symbol reading, successfulreading of the machine-readable symbol 24A, 24B, and unsuccessfulreading of the machine-readable symbol 24A, 24B, respectively.

[0062] Similarly, an alpha-numeric display 94 (FIG. 7) can employ afirst set of words 96 to indicate RFID tag activities and a second setof words 98 to indicate symbol reading activities. (Again, typicallyonly a single word will be displayed at a time, although multiple areshown in FIG. 7 for the convenience of this description.) The display 94is self-explanatory and in the interest of brevity will not be furtherdescribed. Other visual indications, as well as audio and tactileindications are of course possible.

[0063] Selected Methods of Operation

[0064] Different methods of operating the reader 10 or a reader havingsimilar capabilities are disclosed below. As set out in the belowmethods, the intuitive and consistent operation of the user interfacewithin and across operating modes can provide numerous benefits. Whileseveral methods are set out for illustration, other methods employingsimilar techniques are within the scope of the invention. Also, thefollowing descriptions employ certain descriptions of user outputs(e.g., Beep, Click, Red LED, Yellow LED, and Green LED) for convenienceof description. Those skilled in the art will appreciate that othersounds, colors, visual, tactile indications, and/or otherhuman-perceptible indications could be used.

[0065] Single Tag Read Mode

[0066]FIG. 8 shows a method 100 of reading RFID tags 12A-12B (FIG. 1)employing the reader 10 (FIGS. 1-3). Turning on the reader 10, orswitching into the RFID tag reading mode, can automatically cause themicroprocessor 46 to start the method 100 in step 102. Alternatively, oradditionally, the user can cause the microprocessor 46 to start the RFIDtag reading method 100 by selecting an appropriate key from the keypad60 or icon from the display 74. Upon starting in step 102, themicroprocessor 46 can perform an initialization process, for exampleloading appropriate operating instructions from the ROM 50 to the RAM48, initializing the characteristic data string buffer 49 and/orperforming a series of systems checks on the various component andsubsystems of the reader 10, as set out in step 104.

[0067] Under the instructions loaded in the RAM 48, the microprocessor46 activates the radio 44 in step 106. In step 108, the radio 44receives data from the RFID tags 12A, 12B. The radio 44 can emit aninterrogation signal to cause the RFID tags 12A, 12B to respond, or, theradio 44 can simply receive signals from RFID tags 12A, 12B that emitsignals without interrogating the RFID tags. A variety of passive,active and hybrid RFID tags 12A, 12B are known in the art and will notbe discussed in further detail. A discussion of RFID tags can be foundin commonly assigned patent applications: U.S. Ser. No. 09/173,539,filed Oct. 15, 1998, entitled WIRELESS MEMORY DEVICE AND METHOD OFMANUFACTURE (Atty. Docket No. 480062.630); U.S. Ser. No. 09/164,203,filed Sep. 30, 1998, entitled MEMORY TAG AND METHOD OF MANUFACTURE(Atty. Docket No. 480062.632); U.S. Ser. No. 09/173,137, filed Oct. 15,1998, entitled RF TAG HAVING STRAIN RELIEVED STIFF SUBSTRATE ANDHYDROSTATIC PROTECTION FOR A CHIP MOUNTED THERETO (Atty. Docket No.480062.635); and U.S. Ser. No. 09/164,200, filed Sep. 30, 1998, entitledCHIP PLACEMENT ON SMART LABELS (Atty. Docket No. 480062.642).

[0068] In step 110, the microprocessor 46 determines whether duplicatetag data should be suppressed. If suppressed, previously read oracquired data will not be stored or reported a second time. Suppressioncan be a user selection, or can be a selection transferred from the host23, or can be preset, for example by the reader manufacturer or owner.If suppression is not active, the reader 10, in step 112, automaticallytransmits the read data, for example to the host 23, and provides anindication to the user that the data has been received and transmitted.To provide the indication, the reader 10 activates the speaker 66 toemit a single “beep” and activates the Green RFID related LED 76 for ashort time, in steps 114, 116, respectively. Control passes to an end ofthe routine 100, in step 118.

[0069] If suppression is active, the microprocessor 46, compares acharacteristic data string from the received data to othercharacteristic data strings stored in the characteristic data stringbuffer 49, in step 120. The characteristic data string can be any stringof characters stored in the RFID tags 12A, 12B that permit the reader 10to determine whether a particular RFID tag 12A, 12B has been read morethan once. For example, the characteristic data string can be a uniqueidentifier programmed into each of the RFID tags 12A, 12B.Alternatively, the characteristic data string can be the entire set ofdata stored in the RFID tag 12A, 12B, or can be any subset or field ofdata recognizable by position, offset, delimiter or other such fieldidentifier. The microprocessor 46 branches at step 122 based on thedetermination of whether the received characteristic data stringcorresponds, or matches, any of the stored data strings.

[0070] If the received characteristic data string corresponds to, ormatches, any of the stored characteristic data strings, the reader 10provides an indication that the RFID tag 12A, 12B has been read again,activating the speaker 66 to emit a single “click” and activating or“flashing” the Red RFID related LED 84 in steps 124, 126, respectively.The microprocessor 46 determines in step 128, if the reader 10 isfinished reading RFID tags 12A, 12B, as described in detail below.

[0071] If the received characteristic data string does not correspondto, or match any of the stored data strings, the microprocessor 46updates the characteristic data string buffer 49 containing the readcharacteristic data strings, for example storing the newly receivedcharacteristic data string to the buffer 49 in step 130. The reader 10can automatically transmit the read data in step 132, for example to thehost 23 (FIG. 1). The reader 10 also provides an indication that a newRFID tag 12A, 12B has been read (e.g., read for the first time since thebuffer 49 was initialized), activating the speaker 66 to emit a “beep”in step 134 and activating the Green RFID related LED 76 in step 136.Control passes to the end of the routine 100 in step 118.

[0072]FIG. 9 is a flowchart of a method 200 of determining when a reader10 is finished reading. The microprocessor 46 can execute this method200 in place of each step labeled “DONE” in the various other methods,such as at step 128 of FIG. 8 (discussed above), or in the other Figures(discussed below). As set out in the Figures, the method 200, startingat step 202, acts as a function or subroutine, returning a Boolean value(e.g., TRUE/FALSE, YES/NO, or DONE/NOT DONE conditions). While themethod 200 could be implemented as an integral part of the other methodsdiscussed herein, it is set out separately for ease of discussion.

[0073] At step 240, the microprocessor 46 determines whether the trigger20 has been released. A trigger release indicates that the user isfinished reading. If the trigger 20 has been released, themicroprocessor 46 sets the Boolean value to “DONE” at step 242, andpasses control to an end of the routine 200 at step 218, returning theappropriate Boolean value. For example, when returning to the method 100(FIG. 8), the condition “DONE” can cause the reader 10 to stopinterrogating RFID tags 12A, 12B.

[0074] If the trigger 20 has not been released, the microprocessor 46 instep 244 determines whether a timeout condition has been exceeded. Forexample, the reader 10 can assume that all RFID tags 12A, 12B have beenread if a new (e.g., not previously read) tag is not found after somelength of time or some number of consecutive repeatedly read RFID tags12A, 12B. While the length of time or number of repeated reads can bepreset, the length or number of repeats can also be determined duringthe reading, for example as a function of RFID tag density (e.g., numberof RFID tags per unit time). The microprocessor 46 can rely on aninternal clock or a separate clock circuit (not shown) in measuring thetimeout period. Employing RFID tag density to calculate the stoppingcondition “on the fly” reduces the likelihood of ending a searchprematurely.

[0075] If the timeout condition is exceeded, the reader 10 considersreading to be finished, sets the Boolean value to “DONE” at step 242,and passes control to the end of the method 200 at step 218, producingthe appropriate Boolean value for determining the next operation, suchas turning the radio OFF. If the timeout condition is not exceeded, themicroprocessor 46 determines whether a stop command has been receivedfrom the host 23 in step 246. If a stop command has been received, theBoolean value is again set to “DONE” at step 242, and control passes tothe end of the method 200 at step 218. If a stop command has not beenreceived from the host 23, the microprocessor 46 at step 248, determineswhether all RFID tags 12A, 12B have been read. If all RFID tags 12A, 12Bhave been read, the Boolean value is set to “DONE” at step 242 andcontrol passes to the end of the method 200 at step 218, returning theappropriate response. If all RFID tags 12A, 12B have not been read, theBoolean value is set to “NOT DONE” at step 250 and control passes to theend 218, thereby returning the appropriate Boolean value.

[0076] Multi Tag Read/Write Modes

[0077]FIG. 10, shows an additional, or alternative embodiment ofoperating under the present invention. Similar steps in the methods areassigned reference numerals that have the two least significant digitsin common (e.g., the “Start” step is respectively numbered: 102, 202,302, . . . , 702 in FIGS. 6-12, respectively).

[0078]FIG. 10 shows a method 300 of reading multiple RFID tags 12A, 12B(FIG. 1) employing the reader 10 (FIGS. 1-3). In a similar fashion tothe method 100, the microprocessor 46 starts executing the method 300 atstep 302, initializing the reader 10 at step 304, turning ON the radio44 in step 306, and receiving responses from the RFID tags 12A, 12B instep 308. In step 320, the microprocessor 46 compares a characteristicdata string from the received data to other characteristic data stringsstored in the characteristic data string buffer 49 to determine whetherthe reader 10 has read the particular RFID tag 12A, 12B before. Themicroprocessor 46 branches at step 322 based on the determination ofwhether the received characteristic data string corresponds, or matches,any of the stored data strings.

[0079] If the received characteristic data string corresponds to, ormatches, any of the stored characteristic data strings, themicroprocessor 46 adds the read characteristic data string to thecharacteristic data string buffer 49, at step 330. The reader 10provides an indication that the read RFID tag 12A, 12B has beenpreviously read, activating the speaker 66 to emit a single “click” andactivating or “flashing” the Red RFID related LED 84 at steps 352 and354, respectively. In step 356, the microprocessor 46 examines a counter(“Retry”) to determine whether a maximum number of iterations has beenexceeded without finding a “new” (e.g., not previously read) RFID tag12A, 12B. If the number of iterations without encountering a new RFIDtag 12A, 12B has been exceeded, control passes to an end of the method300 at step 318. If the number of iterations without encounter a newRFID tag 12A, 12B has not been exceeded, the microprocessor 46increments the Retry counter in step 358, and determines in step 328whether the reader 10 is finished reading RFID tags 12A, 12B, asdescribed in detail above with respect to method 200 (FIG. 9). Themicroprocessor 46 returns to receiving RFID tag responses in step 308,or passes control to the end of the method 300 at step 318 based on theBoolean value returned by the method 200 (FIG. 9).

[0080] If the received characteristic data string does not correspondto, or match any of the stored data strings, the microprocessor 46resets the Retry counter in step 360, and adds the read characteristicdata string to the characteristic data string buffer 49 in step 362. Thereader 10 in step 364, automatically transmits the read data, forexample to the host 23. The reader 10 also provides an indication that anew RFID tag 12A, 12B has been read (e.g., read for the first time sincethe buffer 49 was initialized), activating the speaker 66 to emit a“beep” in step 314 and activating the Green RFID related LED 76 in step316. The microprocessor 46 determines in step 328 whether the reader 10is finished reading RFID tags 12A, 12B, as described in detail abovewith respect to method 200 (FIG. 9). The microprocessor 46 returns toreceiving RFID tag responses in step 308 or passes control to the end ofthe method 300 in step 318 based on the condition returned by the method200.

[0081] Inclusive Search

[0082] The reader 10 can perform an “inclusive” search, such as findingall RFID tags 12A, 12B on a list of RFID tags 12A, 12B. FIG. 11 shows amethod 400 for performing an inclusive search. The user can start theinclusive search 400 by, for example, selecting an appropriate key oricon as in step 402. The microprocessor 46 performs an initialization atstep 404, for example loading a list of characteristic data strings forthe RFID tags 12A, 12B to be located or identified into thecharacteristic data string buffer 49. The list of characteristic datastrings can, for example, be downloaded from the host 23 via interface22. The microprocessor 46 turns ON the radio 44 at step 406.

[0083] In step 408, the radio 44 interrogates the RFID tags 12A, 12B toreceive response signals containing the respective characteristic datastrings. Alternatively, the radio 44 can receive the response signalswithout interrogating if the RFID tags 12A, 12B are active andperiodically transmit data without requiring initiation by aninterrogation signal. In step 420, the microprocessor 46 compares thereceived characteristic data string with the characteristic data stringsstored in the characteristic data string buffer 49. The microprocessor46 branches at step 422, based on the determination of whether thereceived characteristic data string corresponds, or matches, any of thestored data strings.

[0084] If the read characteristic data string corresponds to, or matchesany of the stored characteristic data strings, then one of the RFID tags12A, 12B has been found and the reader 10 reports such to the userand/or host 23. The reader 10 provides the user indication by activatingthe speaker 66 to “beep” in step 414 and activating or “flashing” theGreen RFID related LED 76 in step 416. If the read characteristic datastring does not correspond to, or match any of the stored characteristicdata strings, then one of the RFID tags 12A, 12B has not been found, andthe reader 10 reports such to the user, and/or host 23. The reader 10provides the user indication by activating the speaker 66 to “click” instep 424 and activating or “flashing” the Red RFID related LED 84 instep 426.

[0085] After providing the user indications, the microprocessordetermines whether the reader is finished reading, in step 428. If thereading is finished, the returned Boolean value (i.e., DONE) causescontrol to pass to an end of the inclusive search routine 400 in step418. If the reading is not finished, the returned Boolean value (i.e.,NOT DONE) causes the radio 22 to continue receiving response signals,passing control to step 418.

[0086] Exclusive Search

[0087] The reader 10 can perform an “exclusive” search, such as findingany RFID tags 12A, 12B not on a list of RFID tags 12A, 12B. FIG. 12shows a method 500 for performing an exclusive search. The user canstart the exclusive search 500 at step 502 by, for example, selecting anappropriate key or icon. The microprocessor 46 performs aninitialization at step 504, for example loading a list of characteristicdata strings for the RFID tags 12A, 12B to be located. At step 506, themicroprocessor turns ON the radio 44.

[0088] In step 508, the radio interrogates the RFID tags 12A, 12B toreceive response signals containing the respective characteristic datastrings. Alternatively, the radio can receive the response signalswithout interrogating if the RFID tags 12A, 12B are active andperiodically transmit without requiring an interrogation signal. In step520, the microprocessor 46 compares the received characteristic datastring with the characteristic data strings stored in the characteristicdata string buffer 49. The microprocessor 46 branches at step 566, basedon the determination of whether the received characteristic data stringdoes not correspond, or match, any of the stored data strings.

[0089] If the read characteristic data string does not correspond to, ormatch any of the stored characteristic data strings, then one of theRFID tags 12A, 12B missing from the list has been found, and the reader10 reports such to the user and/or host 23. The reader 10 provides theuser indication by activating the speaker 66 to “beep” in step 514, andactivating or “flashing” the Green RFID related LED 76 in step 516. Ifthe read characteristic data string corresponds to, or matches any ofthe stored characteristic data strings, then one of the RFID tags 12A,12B missing from the list has not been found, and the reader 10 reportssuch to the user, and/or host 23. The reader 10 provides the userindication by activating the speaker 66 to “click” in step 524, andactivating or “flashing” the Red RFID related LED 84 in step 526.

[0090] After providing the user indications, the microprocessor 46determines whether the reader 10 is finished reading, in step 528. Ifthe reading is finished, the returned Boolean value (i.e., DONE) causescontrol to pass to an end of the exclusive search routine 500 in step518. If the reading is not finished, the returned Boolean value (i.e.,NOT DONE) causes the radio to continue receiving response signals,passing control to step 508.

[0091] Association of RFID Tag Data With Item Using Machine-ReadableSymbol

[0092] Often a user desires to make a physical association between thedata read from one of the RFID tags 12A, 12B and a particular object oritem 14 (FIG. 1). While the RFID tag 12A, 12B may be attached to, orcontained with the item, it can be difficult to identify the particularRFID tag 12A, 12B that is being read. For example, trying to identifyone or more bags in a cargo hold, or cargo container on an airliner isdifficult and time consuming using only RFID tags 12A, 12B. Each bagwould have to be isolated and the RFID tag 12A, 12B read to ensure thatthe read data came from the RFID tag 12A, 12B associated with theparticular bag. At least one proposed solution involves placinghuman-perceptible indicators on each of the RFID tags, as disclosed inthe commonly assigned U.S. Ser. No. 09/______, filed, 1999, and entitled“METHOD AND APPARATUS FOR HUMAN-PERCEPTIBLE IDENTIFICAITON OF MEMORYDEVICES, SUCH AS RFID TAGS” (Atty. Docket No. 480062.663). This solutioncan be relatively expensive since each RFID tag 12A, 12B requires itsown human-perceptible indicator which complicates RFID tag manufacture.

[0093]FIG. 13 shows a method 600 of associating the read data from theRFID tag 12A, 12B with a particular one of the items 14. The associationmethod 600 assumes that an RFID tag 12A, 12B has already been read, acharacteristic data string retrieved and stored, for example, in thecharacteristic data string buffer 49. The user can start the associationmethod 600 in step 602, as discussed generally above. Alternatively, thereader 10 can be configured to automatically start the associationmethod 600 at step 602. In step 668, the microprocessor 46 enters thesymbol reading mode. The user activates the trigger 20 in step 670,causing the microprocessor 46 to activate the image sensor 52 to readthe machine-readable symbol 24A, 24B at which the reader 10 is directed.In step 672, the image sensor 52 acquires data from the machine-readablesymbol 24A, 24B by scanning, digitizing, or by any commonly knownmethods in the relevant art. As part of acquiring the data, themicroprocessor 46, or a dedicated processor (not shown), decodes theimage to acquire a characteristic data string encoded in themachine-readable symbol 24A, 24B. Methods and apparatus for acquiringdata from machine-readable symbols are commonly known in the art, andare specifically taught in The Bar Code Handbook 3^(rd) Ed(, by Palmer,Roger C, Helmers Publishing, Inc. (ISBN 0-911261-09-5), and, in theinterest of brevity, will not be described in further detail.

[0094] To determine whether the machine-readable symbol 24A, 24B thatthe reader 10 is pointing at is associated with the RFID tag data readby the reader 10, the microprocessor 46 compares a characteristic datastring read from the RFID tag 12A, 12B with the characteristic datastring read from the machine-readable symbol 24A, 24B, in step 620. Theuser can visually associate the RFID tag 12A, 12B with themachine-readable symbol 24A, 24B since the RFID tag 12A includes themachine-readable symbol 24A, or the RFID tag 12B and machine-readablesymbol 24B are carried by the same item 14, or can be visuallyassociated is some other manner. The user can therefore determine thatthe data is from a particular RFID tag 12A, 12B when a match isindicated by the reader 10.

[0095] If the characteristic data string from the machine-readablesymbol 24A, 24B corresponds to, or matches, the characteristic datastring from the RFID tag 12A,12B, the reader 10 provides an indicationthat an association exists. To provide the indication, themicroprocessor 46 activates the speaker 66 to emit a single “beep” instep 614 and activates or “flashes” the Green RFID related LED 76 andthe Green symbol related LED 78 in step 674. The RFID related and thesymbol related LEDs 76, 78 are each activated, indicating that both anRFID tag 12A, 12B and a machine-readable symbol 24A, 24B have beenlocated, providing a consistency across the user interface.

[0096] In step 676, the microprocessor 46 can turn OFF the image sensor52 after having found an association. In step 612, the reader 10 canreport the data, for example transmitting the RFID data to the host 23via the communications port 38 and interface 22. In step 676, the reader10 can receive a direction or command from the host 23 via the interface22 and the communications port 38. In step 678, the microprocessor 46determines whether the buffer should be modified based on the commandfrom the host 23. If the buffer is to be modified, the microprocessor 46modifies the buffer at step 680, and passes control to an end of theassociation method 600 in step 618. Otherwise, the microprocessor 46passes control directly to the end of the association method, in step600, without modifying the buffer.

[0097] If the characteristic data string from the machine-readablesymbol 24A, 24B does not correspond to, or match the characteristic datastring from the RFID tag 12A,12B, the reader 10 provides an indicationthat an association does not exist. To provide the indication, themicroprocessor 46 activates the speaker 66 to emit a three “Beeps” instep 682, and activates or “flashes” the Red RFID related LED 84 and theGreen symbol related LED 78 in steps 626, 684, respectively. The Greensymbol related LED 78 is flashed to indicate that a symbol has beensuccessfully read, while the Red RFID related 84 is flashed to indicatethat the data is not associated with the machine-readable symbol 24A,24B, further providing consistency across the user interface. Themicroprocessor 46 proceeds to the end of the method 600, in step 618.

[0098] Automatically Reading a Symbol Based on Proximity to RFID Tag, orFrequency of RFID Tag's Responses

[0099]FIG. 14 shows a method 700, in which the reader 10 automaticallyreads the machine-readable symbol when the reader 10 is within a definedproximity of the RFID tag 12A, and hence within the defined proximity ofthe machine-readable symbol 24A. The automated symbol reading featureprovides numerous benefits, for example the automated symbol readingfeature can simplify operation of the reader, and/or reduce theprobability of user error. The automated symbol reading feature can alsoreduce the amount of labor required to operate the reader 10, and caneven eliminate the need for a human operator. The method 700 of FIG. 14can be used as part of, or with, many of the previously describedmethods.

[0100] The antenna 42 in the reader 10 can be directionally sensitive.The directionally sensitive antenna 42 has a directional range, in otherwords, the antenna is more sensitive in certain directions than otherdirections. As the reader 10 approaches a particular RFID tag 12A, 12B,that RFID tag 12A, 12B spends a higher percentage of time within therange of the reader 10. In contrast, other RFID tags 12A, 12B are in therange a lower percentage of time. Thus, as the reader 10 comes within apredefined proximity of the RFID tag 12A, 12B, the number of “hits”(i.e., reading an RFID tag having a desired characteristic data string)will increase, and the number of “misses” (i.e., reading RFID tags nothaving the desired characteristic data string) will decrease. The usermay recognize this from an increase in the number of “Beeps” and adecrease in the number of “Clicks” emitted by the reader 10. Themicroprocessor 46 in the reader 10, can keep track of the number of hitsand the number of misses for some unit length of time, steps 786, 788,respectively. The microprocessor 46 can determine a ratio of the numberof hits per unit of time and the number of misses per unit of time.Alternatively, the host 23 can process the same information.

[0101] In step 790, the microprocessor 46 determines whether the ratioof hits to misses exceeds a symbol reading threshold. If the ratio doesnot exceed the symbol reading threshold, the microprocessor 46 returnsto step 786 and the reader 10 continues to read the RFID tags 12A, 12B,continually revising and checking the ratio against the threshold.

[0102] If the ratio exceeds the symbol reading threshold, themicroprocessor 46 turns the image sensor 52 ON, for example, switchingfrom the RFID reading mode to the symbol reading mode in step 768. Themicroprocessor 46 controls the image sensor 52 to image and decode themachine-readable symbol 24A, 24B in 772. In step 774, the microprocessor46 turns the image sensor 52 OFF, thereby conserving power. In step 720,the microprocessor 46 compares the characteristic data string from themachine-readable symbol 24A, 24B to the characteristic data string fromthe RFID tag 12A, 12B.

[0103] If the characteristic data string from the machine-readablesymbol 24A, 24B corresponds to, or matches, the characteristic datastring from the RFID tag 12A,12B, the reader 10 provides an indicationthat an association exists. To provide the indication, themicroprocessor 46 activates the speaker 66 to emit a single “Beep” instep 714 and activates or “flashes” the Green RFID related LED 76 andthe Green symbol related LED 78 in step 774. The RFID related and thesymbol related LEDs 76, 78 are each activated, indicating that both anRFID tag 12A, 12B and a machine-readable symbol 24A, 24B have beenlocated, providing a consistency across the user interface.

[0104] In 712, the reader 10 can report the data, for exampleautomatically transmitting the RFID data to the host 23 via thecommunications port 38 and interface 22. In step 776, the reader 10 canreceive a direction or command from the host 23 via the interface 22 andthe communications port 38. In step 778, the microprocessor 46determines whether the characteristic data string buffer 49 should bemodified based on the command from the host 23. If the buffer 49 is tobe modified, the microprocessor 46 modifies the buffer at step 780, andpasses control to an end of the association method 700 at step 718.Otherwise, the microprocessor 46 passes control directly to the end ofthe association method 700 at step 718 without modifying thecharacteristic data string buffer 49.

[0105] If the characteristic data string from the machine-readablesymbol 24A, 24B does not correspond to, or match the characteristic datastring from the RFID tag 12A,12B, the reader 10 provides an indicationthat the association does not exist. The microprocessor 46 activates thespeaker 66 to emit three “Beeps” in step 782, and activates or “flashes”the Green symbol related LED 78 and the Red RFID related LED 84 in steps784 and 726, respectively. The Green symbol related LED 78 is flashed toindicate that a symbol has been successfully read, while the Red RFIDrelated 84 is flashed to indicate that the data is not associated withthe machine-readable symbol 24A, 24B, further providing consistencyacross the user interface.

[0106] Summary

[0107] The various embodiments described above can be combined toprovide further embodiments. All of the above U.S. patents, patentapplications and publications referred to in this specification areincorporated by reference. Aspects of the invention can be modified, ifnecessary, to employ systems, circuits and concepts of the variouspatents, applications and publications to provide yet furtherembodiments of the invention.

[0108] Although specific embodiments of and examples data carrierreaders and reading are described herein for illustrative purposes,various equivalent modifications can be made without departing from thespirit and scope of the invention, as will be recognized by thoseskilled in the relevant art. The teachings provided herein of theinvention can be applied to any data carrier reader, not necessarily theexemplary combination RFID tag and symbol reader generally describedabove.

[0109] For example, some of the structures and methods can be used withreaders capable of reading only RFID tags. Some of the structures andmethods can be used with readers capable of reading onlymachine-readable symbols. Some of the structures and methods can besuitable with readers for other data carriers, such as optical tags andtouch memory devices. The methods and structures are generallyapplicable with other wireless memory devices, not just radio frequency,and the term RFID as used herein is meant encompass wireless memorydevices operating in all ranges of the electromagnetic spectrum, notonly the radio frequency portion. Similarly, the structures and methodsdisclosed can work with any variety of modulation techniques, including,but not limited to, amplitude modulation, frequency modulation, phasemodulation and/or pulse width modulation. The structures and methods canalso be applied to various machine-readable symbologies, including, butnot limited to, bar codes, stacked codes, area and/or matrix codes. Theimage sensor 52 can be any type of image capture device, including laserscanners, one- and two-dimensional charged coupled devices, Vidicons,and the like.

[0110] These and other changes can be made to the invention in light ofthe above-detailed description. In general, in the following claims, theterms used should not be construed to limit the invention to thespecific embodiments disclosed in the specification and the claims, butshould be construed to include all apparatus and methods that operate inaccordance with the claims. Accordingly, the invention is not limited bythe disclosure, but instead its scope is to be determined entirely bythe following claims.

We claim:
 1. A multi-purpose data carrier reader, comprising: a symbolreading section including an image sensor to image machine-readablesymbols; an RFID tag reading section including a radio to interrogateRFID tags; a first set of human-perceptible indicators coupled to thesymbol reading section for control thereby to produce human-perceptibleindications in response to at least one symbol reading activity; and asecond set of human-perceptible indicators, different from the first setof human-perceptible indicators and coupled to the RFID tag readingsection for control thereby to produce human-perceptible indications inresponse to at least one RFID tag reading activity.
 2. The reader ofclaim 1 wherein each of the first and second sets of human-perceptibleindicators include a respective light emitting diode of a first color,the first color light emitting diode in the first set ofhuman-perceptible indicators being activated when a machine readablesymbol is successfully read and the first color light emitting diode inthe second set of human-perceptible indicators being activated when anRFID tag is successfully read.
 3. The reader of claim 1 wherein thefirst set of human-perceptible indicators produces a firsthuman-perceptible signal when a machine readable symbol is successfullyread; and the second set of human-perceptible indicators produces thefirst human-perceptible signal when an RFID tag is successfully read. 4.The reader of claim 1 wherein the first set of human-perceptibleindicators produces a first human-perceptible signal when a first symbolreading activity occurs; and the second set of human-perceptibleindicators produces the first human-perceptible signal when acorresponding RFID reading activity occurs.
 5. The reader of claim 1wherein the first and second set of human-perceptible indicators arevisual indicators.
 6. The reader of claim 1 wherein the first and secondset of human-perceptible indicators are light emitting diodes.
 7. Thereader of claim 1 wherein the first and second set of human-perceptibleindicators are visual indicators are icons displayed on a display. 8.The reader of claim 1 wherein the first and second set ofhuman-perceptible indicators are visual indicators are alpha-numericcharacters displayed on a display.
 9. The reader of claim 1 wherein thefirst and second set of human-perceptible indicators are sounds emittedfrom an audio source.
 10. The reader of claim 1 wherein the first andsecond set of human-perceptible indicators are vibrations emitted by atactile source.
 11. A multi-purpose data carrier reader, comprising: asymbol reading section including an image sensor to imagemachine-readable symbols; an RFID tag reading section including a radioto interrogate RFID) tags; and a mode switch configured to switchoperation between the symbology reader section and the RFID tag readersection.
 12. The reader of claim 11 wherein the mode switch is a userselectable switch.
 13. The reader of claim 11 wherein the mode switch isa user selectable membrane switch.
 14. The reader of claim 11 whereinthe mode switch is responsive to a command signal from an external hostdevice.
 15. The reader of claim 11 wherein the mode switch provides acommand signal to an external host device.
 16. The reader of claim 11wherein the mode switch is responsive to at least a portion of data in apreviously read data carrier.
 17. The reader of claim 11 wherein themode switch is a trigger responsive to select a mode based on a numberof successive trigger activations.
 18. The reader of claim 11 whereinthe mode switch is a trigger responsive to select a mode based on aduration of trigger activation.
 19. The reader of claim 11 , furthercomprising a first number of visual indications corresponding to asymbol mode and a second number of visual indicators corresponding to anRFID mode, wherein the mode switch has at least a first and a secondpositions, the first and second positions oriented to provide a visualindication consistent with the positions of the visual indicators.
 20. Amethod of operating a data carrier reader, comprising: selecting one ofat least two human-recognizable temporal indication patterns based on acurrent operation of the data carrier reader, where thehuman-recognizable temporal indication patterns each correspond to arespective temporal user indication; and projecting light substantiallyoutward of the data carrier reader to form the selectedhuman-recognizable temporal indication pattern.
 21. The method of claim20 wherein projecting the light includes successively flashing the lightto produce the selected human-recognizable temporal indication pattern.22. The method of claim 20 wherein projecting the light includesselectively flashing a first color light and a second color light toproduce the selected human-recognizable temporal indication pattern. 23.The method of claim 20 wherein projecting the light includes modulatinga laser to produce the selected human-recognizable temporal indicationpattern.
 24. The method of claim 20 , further comprising: modulating alaser while in an RFID reading mode to produce the selectedhuman-recognizable temporal indication pattern; and illuminating asymbol with the laser in a symbol reading mode to scan the symbol.
 25. Adata carrier reader, comprising: a first light source substantiallyalignable with a data carrier; a processor coupled to control the firstlight source to produce a selected one of at least twohuman-recognizable temporal indication patterns based on a readeroperation, where each of the human-recognizable temporal indicationpatterns correspond to a respective temporal user indication.
 26. Thedata carrier reader of claim 25 wherein the processor is coupled tocontrol the first light source to produce a scanning beam across thedata carrier in a symbol reading mode, and to produce the selectedhuman-recognizable indication pattern in an RFID reading mode.
 27. Thedata carrier reader of claim 25 wherein the selected human-recognizableindication pattern includes a number of successively timed flashes oflight.
 28. The data carrier reader of claim 25 wherein the selectedhuman-recognizable indication pattern includes a number of differentcolor flashes of light, successively timed.
 29. A method of operating adata carrier reader having a laser, comprising: producing a firstscanning laser beam with the laser in a symbol reading mode; andproducing a human-recognizable temporal indication pattern based on areader operation in an RFID reading mode.
 30. The method of claim 29 ,further comprising: selecting the human-recognizable temporal indicationpattern from a number of human-recognizable temporal indicationpatterns, the human-recognizable temporal indication patternscorresponding to respective temporal user indications.